Electric circuit breaker



Patented July 24, y1934 UNITED STATES ELECTRIC CIRCUIT BREAKER CharlesBresson, Villeurbanne, France, assgnor to Ateliers de ConstructionsElectriques de- Delle, Paris, France Application January 23, 1934,Serial No. 707,946 In Germany January 31, 1933 6 Claims. (Cl 20o- 150) lAn electric circuit-breaker is known in which an arc extinguishingchamber is entirely or partially iilled with an insulating or conductingliquid, the arc being extinguished in said chamber by the gases orvapors produced by the arc itself. The infiuenceof such an extinguishingchamber is particularly effective with high intensity currents, for inthis case the energy dissipated by the arc for its own extinction is 10very great. 0n the contrary, with low intensity I currents the energydissipated by the arc is often insumcient and the extinction of the arcuncertain, and this particularly so when the power factor is very low.'I'he present invention rem- Vedies this disadvantage by injecting a jetof liquid into the extinguishing chamber during the separation of thecontacts.

In accordance with the present invention said jet of liquid is directedtowards the fixed contact situated outside said chamber. g

In a circuit-breaker of this type, and in view of obtaining a constantduration of arc extinction independently of the intensity of thecurrent, the energy needed for the extinction of the arc is drawn fromthe arc itself when the cur- 'rent is of high intensity and from anexternal source for low intensity currents. 'I'he injection of liquidmay take place from the very start of the contact opening operation ormay only take 3o place during the latter part of said operation.

'Ihe liquid is preferably injected in an inverse direction to thedisplacement of the movable contact.

The invention and its aims and objects will be readily understood fromthe following descripltion, taken in connection with the accompanyingdiagrammatic drawing of one illustrative embodiment of the invention.

In the drawing, the extinguishing chamber i o is enclosed in vessel 2lled with oil to level 3.

Said chamber is provided with two openings 4` and 4' constitutingnozzles. The lateral walls of said chamber are prolonged downwardsbeyond nozzle 4'. The prolonged portion of said walls 5 situated belownozzle 4' is provided with a plurality of apertures 11 of comparativelylarge area. In certain embodiments, several superposed stages ofapertures 11 may be used. Below cylindrical chamber land in the axis ofsame is disposed xed contact' constituted by a tube mounted on a spring.The movable contact is also constituted by a tube 6 capable of beingdisplaced along the axis of chamber 1 and capable of traversing nozzles4 of said chamber. In the upper part of said tube 6 holes 12 areprovided,

said holes enabling said tube 6 to communicate with the liquid containedin vessel 2. In the interior of tube 6 is disposed a piston 7 connectedto the fixed portion of the apparatus through rod 8. The combination ofthese members constituting the movable contact take the form of acylinder 9 filled with the liquid contained in vessel 2. The extremityof said cylinder is terminated by the lower orifice of tube 6 which atthis point is narrowed down to constitute the nozzle 10.

On opening the circuit-breaker and from the instant when tube 6 issufficiently raisedto locate said holes 12 above piston 7, the oilcontained in cylinder 9 is injected into chamber 1 approximately alongthe axis of the arc which is drawn out in said chamber approximately ina straight -line between contacts 5 and 6. By suppressing said holes 12the injection will take place from itzhevery beginning of the separationof the conac s.

The shape and diameter of nozzle 10 are so chosen that the velocity ofinjection and the quantity of oil injected will ensure the extinction ofarcs of low intensity which would not otherwise be extinguished withsuiiicient rapidity by the sole energy liberated by the arc in theinterior of said chamber.

Injection of liquid always takes place whatever the intensity of thecurrent to be interrupted. It should .however be noted that with highintensity currents the pressure exerted by the arc itself within themass of oil enclosed in chamber 1 is suflicient in itself for theextinction of the arc and that the injection of liquid has but littleinuence toward said extinction. lThis injection only becomes effectivewhen, by reason of the low intensity of the current to be interrupted,the energy liberated by the arc is small.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

1. In an electric circuitbreaker, a vessel containing a liquid, a fixedcontact in said liquid, a stationary extinguishing chamber filled 4withliquid disposed above said contact, said extinguishing chamber providedwith two nozzles, a movable contact disposed so as to be capable ofdisplacement within said extinguishing chamber by passing through saidtwo nozzles, and meansfor injecting a liquid in said extinguishingchamber, in a direction directed towards said fixed contact.-

2. In an electric circuit-breaker, a vessel containing a liquid, a iixedcontact'in said liquid, a stationary extinguishing chamber lled withliquid disposed above said contact, said extinguishing chamber providedwith an upper nozzle and a lower nozzle, the axes of said nozzlescoinciding with the axis of said fixed contact, a movable contactdisposed so as to be capable of displacement in the axis of saidextinguishing chamber by passing through said two nozzles, and

`means for injecting a liquid in said extinguishing chamber in adirection directed towards said xed contact, the axis of the jet ofinjected liquid being disposed in the axis of said extinguishingchamber.

3. In an electric circuit-breaker, a vessel containing a liquid,`a.fixed contact in said liquid, above said contact a stationaryextinguishing chamber filled with liquid, said extinguishing chamberprovided with two nozzles, a movable contact traversing saidextinguishing chamber through said two nozzles and disposed so as to becapable of being entirely withdrawn from said extinguishing chamber bypassing through said nozzles, and means for injecting a liquid in saidextinguishing chamber in a direction directed towards said iixedcontact.

4. In an electric circuit-breaker, a vessel containing a liquid, a xedcontact in said liquid, above said contact a stationary extinguishingchamberr filled with liquid, said extinguishing chamber provided withtwo nozzles, a movable contact disposed so as tobe capable ofdisplacement in said extinguishing chamber by passing through said twonozzles, said movable contact filled with liquid. disposed above saidcontact, said extinguishing chamber provided with two nozzles, a movablecontact disposed so as to be capable of displacement within saidextinguishing chamber by passing through said two nozzles, and means forinjecting a liquid in said extinguishing chamber in a direction directedtowards said fixed contact.

, 6. In an electric circuit-breaker, a vessel containing a liquid, aiixed contact in said liquid, a stationary extinguishing chamber filledwith liquid disposed above said contact, said extinguishing chamberprovided with two nozzles, a movable contact disposed so as to becapable of -displacement within said extinguishing chamber by passingthrough said two nozzles, and means for injecting a liquid in saidextinguishing chamber during the latter part of the contact openingoperation in a direction directed towards said fixed contact. i

- CHARLES BRESSON.'

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